PIC16F627A-I/SO Microchip Technology, PIC16F627A-I/SO Datasheet - Page 69

• Manufacturer Part Number: PIC16F627A-I/SO
• Description: IC MCU FLASH 1KX14 EEPROM 18SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F627A-I/SO

• Program Memory Type: FLASH
• Program Memory Size: 1.75KB (1K x 14)
• Package / Case: 18-SOIC (7.5mm Width)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 16
• Eeprom Size: 128 x 8
• Ram Size: 224 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 224 B
• Interface Type: SCI/USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 16
• Number Of Timers: 3
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, DM163014, DM164120-4
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT18SO-1 - SOCKET TRANSITION 18SOIC 300MILI3DBF648 - BOARD DAUGHTER ICEPIC3AC162053 - HEADER INTERFACE ICD,ICD2 18DIPAC164010 - MODULE SKT PROMATEII DIP/SOIC
• Data Converters: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

11.0
The Voltage Reference is a 16-tap resistor ladder
network that provides a selectable voltage reference.
The resistor ladder is segmented to provide two ranges
of V
conserve power when the reference is not being used.
The VRCON register controls the operation of the
reference as shown in Figure 11-1. The block diagram
is given in Figure 11-1.
11.1
The Voltage Reference can output 16 distinct voltage
levels for each range.
REGISTER 11-1:
FIGURE 11-1:
 2004 Microchip Technology Inc.
REF
V
REN
Note:
VOLTAGE REFERENCE
MODULE
Voltage Reference Configuration
values and has a power-down function to
bit 7
bit 6
bit 5
bit 4
bit 3-0
R is defined in Table 17-3.
V
REF
VRCON REGISTER (ADDRESS: 9Fh)
VOLTAGE REFERENCE BLOCK DIAGRAM
bit 7
V
1 = V
0 = V
V
1 = V
0 = V
V
1 = Low Range
0 = High Range
Unimplemented: Read as ‘0’
V
When V
When V
Legend:
R = Readable bit
-n = Value at POR
REN
ROE
RR
R
V
R/W-0
V
<3:0>: V
DD
REN
: V
: V
REF
REF
: V
REF
REF
REF
RR
RR
REF
REF
8R
circuit powered on
circuit powered down, no I
is output on RA2 pin
is disconnected from RA2 pin
Range selection
= 1: V
= 0: V
REF
Enable
Output Enable
R/W-0
V
value selection 0
ROE
REF
REF
R
= (V
= 1/4 * V
R/W-0
R
V
<3:0>/ 24) * V
R
Preliminary
RR
W = Writable bit
‘1’ = Bit is set
DD
16 Stages
PIC16F627A/628A/648A
16-1 Analog Mux
+ (V
V
DD
R
R
U-0
[3:0]
<3:0>/ 32) * V
—
drain
The equations used to calculate the output of the
Voltage Reference are as follows:
The setting time of the Voltage Reference must be
considered when changing the V
(Table 17-3). Example 11-1 demonstrates how Voltage
Reference is configured for an output voltage of 1.25V
with V
DD
R
if V
if V
15
DD
RR
RR
V
= 5.0V.
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
R/W-0
= 1:
= 0:
REF
V
DD
R
R
3
V
=
REF


V
DD
V
=
SS
R/W-0
V
--------------------- -
8R
V
R
1
-- -
4
R
<3:0>


24
2
V
V
+
R
R
3
0
V
--------------------- -
(From VRCON<3:0>)
R
V
x = Bit is unknown
REF
<3:0>
32
SS
R/W-0
V
V
DD
DS40044B-page 67
output
R
1
V
RR
V
DD
R/W-0
V
R
0
bit 0